Lubricating compositions



United S saasass Patented Sept. 2$, liiltiii 3,208,938 LUBRICATING C(DMPOSl'lHONS Hyman Rainer, Florissant, M1, assignor to Shell Oil Company, New York, N.Y., a corporation of Delaware No Drawing. Filed Feb. 8, 1963, Ser. No. 257,067 15 Claims. (Cl. 252-32.5)

This invention relates to improved hydrocarbon lubricants and particularly to mineral lubricating oil compositions which possess good detergency, antiwear, as well as sludge, corrosion or rust inhibiting properties.

It is known that certain non-ash forming polymeric nitrogen-containing compounds in which the nitrogencontaining groups may be amino or amido groups such as vinyl pyridines or vinyl pyrrolidones, function as deter-- gents when added in small amounts to lubricants such as mineral lubricating oils. However, copolymers of this type have been found to lack wear inhibiting properties and are corrosive and under severe conditions of use such as under extreme temperatures and pressure they have been found to be shear unstable resulting in sludgin and other undesirable side effects.

In order to overcome these detects, the art discloses that the addition of basic polyvalent metal salts such as basic alkaline earth metal petroleum sulfonates or aromatic carboxylates such as alkyl salicylatcs, impart wear inhibiting and anti-scul'ling properties to lubricants con taining the above-mentioned non-ash forming detergents. However, it has been observed that the problem of corrosion remains and undesirable side effects such as sludg ing arises due to the apparent complexing tendencies between the nitrogen-containing polymer and the basic metal salts.

It has now been discovered that excellent ash-free deter gent lubricants are provided having in addition Wear and corrosion inhibiting properties as well as being resistant towards sludging tendencies, by dispersing in lubricating oil compositions such as mineral lubricating oils containing polymer nitrogen-containing detergents, a small amount of an oil-soluble complex of a po yamide and an acidic compound selected from the group tonsisting of an alkyl acid phosphate and an alkyl phenoxycarboxylic acid, the complex having the general formula:

R1 1 O [i't( i"---ILl(Cl l I'VE- i l-t iR].(A) x Where R is an alkyl radical of 8 to 22 carbon atoms, i1 is an integer of l to 10, R and R are. hydrogen or C alkyl radicals and (A) is the acidic compt'uiud alkyl acid phosphate having the formula:

chloroalkyl radical, R is a hydtucarbyl radical such as an alkyl, aralkyl, cycloalkyl radical having from 1 to 18 carbon atoms, X is selected from the group consisting of oxygen and sulfur, in can be Zero or one, y is an integer of from 1 to and x in Formula 1 is l or 2.

The detergent nitrogen-containing polymers useful in compositions of the present invention include copolymers of monomers having polymerized linkages and contain ing nitrogen containing groups which may be amino or clave.

amido groups. They may be derived from polymerizabie monomers containing primary, secondary or tertiary (the latter two are preferred) amino nitrogen, including hetero cyclic amino or amido nitrogen-containing substances, having an ethylcnically unsaturated polymerizable group. These detergent polymers may be obtained by polymerising vinyl substituted heterocyclic nitrogen-containing substances such as vinyl pyridine, vinyl picoline and vinyl quinoline, vinyl pyrrolidone or vinyl arylamines such as paraaminostyrene, or polyamines prepared by reacting polymeric epoxy compounds with ammonia or primary or secondary amines, with polymerizable unsaturated alcohols, acids or esters such as acrylates and methacrylates of long chain fatty acids, and the like. The' preferred polymeric amino or amido compounds are those containing tertiary amine groups and particularly those containing heterocyclic amino groups such as obtained by copolymerizing a polymerizable heterocyclic nitrogen base compound with a polymerizable unsaturated material free of heterocyclic nitrogen-containing radicals such as are described in British patent specification 760,544 and US. Patents 2,839,512 and 2,889,282. The copolymers inelude: copolymer of stearyl methacrylate, and 2methyl- S-vinyl pyridine; copolymer of stearyl methacrylate, lauryl methacrylate and Z-methyLS-vinyl pyridine; and those which contain additional C alkyl methacrylates in the polymer, such as copolymers of stearyl methucrylates, lauryl mcthacrylate, methyl methacrylate and Z-mcthyl-S-vinyl pyridine; and similar copolymers in which the methyl methacrylate is replaced by butyl methacrylate and the 2-methyl-5-vinyl pyridine is replaced by 5-ethy1-2-vinyl pyridine; or copolymer of lauryl merit acrylate and N-vinyl pyrrolidone or similar copolymers as described in the British Patent 808,664, and mixtu thereof. Acrylate-vinyl pyrrolidone copolymers are by Rohm & Haas under the designations Acryloid 3.1 C or 917 or 966 and are copolymers of N-vinyl pyrrolidone and lauryl mcthacrylate of varying molecular weights Other suitable polymeric amines are those available com mercially such as those sold by E. I. du Pont de Nemours and Co. under the designations LOA 564 and 565, which are copolymers of lauryl methacrylate and diethylaminoethylmethacrylaie (note US. Patent 2,737,496).

Particularly preferred detergent polymers are Acryloitt 917 and 966 (copolymers of N--vinyl pyrrolidone and lauryl methacrylate in the molecular weight range at 400,000 to 500.000) orthe copolymers of vinyl pyridine and mixtures of dissimilar methacrylate esters, the prep aration of which is illustrated by the following examples.

EXAMPLE I A mixture of 25% of Z-methyLS-vinyl pyridine and stearyl n'te'thacrylate was heated in a 50-50 min ture of benzene and a light mineral oil (East Texas 113d SSU at F. neutral) to about C. at which tirru; 0.25% wt. of ditert. butyl peroxide was added and the reaction mixture was maintained at this temperature for about 6 hours.

At the completion of the reaction, the solvent was stripped off and the polymer diluted with neutral oil to a polymer content of about 30% by weight and filtered at 100-2l0 C. The copolymer had a molecular weight of about 500,000 and a nitrogen content of 2.94%.

EXAMPLE II 30% stearyl methacrylate, 51% lauryl methacrylate, 14% methyl methacrylate and 5.0% 2-methyl-5-vinyt pyridine were charged to a BOO-gallon stainless steel auto- A 50-50 mixture of benzene and neutral pend leum oil was then added to the autoclave so as to furnish 1 part of the mixture per 3 parts of the total monomer.

3 0.25 of ditert.butyl peroxide was then added and the mixture heated at 120 C. for about 7 hours.

At the completion of the reaction, the benzene was stripped off to final conditions of 120 C. and 10 mm. Hg with nitrogen purging. The benzene-free product was then diluted with neutral oil to a polymer content of about 30% by weight and filtered at l120 C. The polymer had a molecular'weight of about 600,000 and a nitrogen content of 0.54%.

The molecular weights of the polymers were determined by the light scattering method.

The second essential additive used in compositions of the present invention is the polyamide complex as represented by Formula I. The cationic portion of the com plex is prepared by reacting a polyamine such as ethylene diamine, propylene diamine, diethylene triamine, triethylene tetraamine, trimethyl trimethylene diamine, hexamethylene diamine, N-2-am-inoethylpiperazine and the like with aliphatic carboxylic acids of from 2 to 22 carbon atoms such as acetic acid, propionic acid, butyric acid, caprylic acid, capric acid, lauric acid, palmitic acid, stearic acid, oleic acid, ricinoleic acid and mixture thereof and comprises reacting approximately equimolecular quantities of a polyamine and a fatty acid at between 120 C. and 250 C. for a periodof or more hours, preferably under atmospheric pressure. For example, 1 mole of alkyl substituted diethylene triamine,

(Ia) I RCONHCH CHN(C H )CH CH NHCOR where R is oleyl radical. Other diamides include distearylamide of ethylene diamine, dilauryl amide of diethylene triamine, dioleyl amide of diethylene triamine, diricinoleyl amide .of diethylene triamine, dioleylamide of N-Z-aminoethyl piperazine and mixtures thereof.

The acid portion of .the complex includes hydrocarbyl acidphosphates, e.g. mono and di-alkyl, mono and dicycloalkyl, diaralkyl, diaryl, alkyl aryl, aralkyl alkyl acid phosphates and their thio derivatives having from 8 to carbon atoms in the molecule. Examples of suitable monoand di-acid and/ or thio acid phosphates are mono and distearyl acid phosphate, mono and dioleyl acid phosphate, mono and dicyclohexyl acid phosphate, dicresyl acid phosphate, lauryl cresyl acid phosphate, dibenzyl acid phosphate, lauryl benzyl acid phosphate, dilauryl acid dithiophosphate, dilauryl thio acid phosphate; alkyl acid phosphonates such as monobutyl chloromethyl phosphonate, monolauryl chloromethyl phosphonate and the like. A preferred alkyl acid phosphate is Lorol acid phosphate, which is a mixture of phosphoric esters of Lorol alcohol. The term Lorol alcohol is used in the trade to denote a mixture of primary normal aliphatic alcohols of 8 to 12 carbon atoms which are obtained by fractionation of the alcohols resulting from the reduction of cocoanut and/or palm kernel oils. Lorol acid phosphate mixtures are readily obtainable on the market and for this reason are preferred to the purified esters of greater'scarci-ty and higher price. One Lorol acid phos phate type is sold underthe trade name Ortholeum 162 and is understood to be mainly a mixture of the mono and diacid phosphates of Lorol alcohol.

The other acid portion of the complex can bean C alkyl phenoxy carboxylic acid such as nonyl phenoxy acetic acid, nonyl phenoxy butyric acid, stearyl phenoxy acetic acid, n-onyl phenoxy propionic acid, and the like.

The complex is prepared by reacting 1 mole of the polyamide with 1 to 2 moles of the acid phosphate and/or alkyl phenoxy carboxylic acid at between 200 C. for a period of from 2-10 hours. Thus, about 1 mol of the dioleylamide (Ia) and 1 mole of a mixture 'ofmono and dilauryl acid phosphate was reacted at 100-150 C. for 5 hours at which time the complexing appeared to be complete and a homogeneous product containing phosphorus was obtained. This complex'is identified as (Ib). Another complex (Ic).was prepared under above described conditions using dioleylamide of N-2-aminoethyl piperazine and a mixture of mono and dilauryl-acid phosphate under conditions described for the preparation of Other complexes include (Id) complex of dioleylamide of ethylene diamine and dilauryl acid phosphate, (Ia) complex of dioleylamide of triethylene triamine and dicl'leyl acid phosphate, (If) distearylamide of triethylene tetramine and monobutyl chloromethyl phosphonate. The complexes with alkyl phenoxy carboxylic acids and the polyamines include (IIa) complex of dioleylamide of (Ia) and nonyl phenoxy acetic acid, (IIb) complex of dioleylamide of N-Z-aminoethylpiperazine and nonyl phenoxy acetic acid, (IIc) eomplexof distearylamide of diethylene triamine and nonyl phenoxy acetic acid, (IId) complex of dioleyl amide of diethylene triamine and nonyl phenoxy butyric acid, (11:2) complex of diricinoleylamide of diethylene triamine and lauryl phenoxy acetic acid and the like.

Although the stability and wear inhibition of various functional fluids such as mineral oils or synthetic lubricants are greatly improved by addition thereto of the complex compounds described, the oxidative stability of such compositions is greatly enhanced and the overall properties of such compositions substantially improved by addition thereto of a small amount (0.0l2% by weight, prefer ably 0.11% by'weight) of a methylene bisphenol such as 1,1-bis Z-hyd roxy-3-t-butyI-S-methylphenyl methane;

bis Z-hyd roxy-3-t-butyl-S-methylphenyl) ethane;

1,1-bis Z-hydroxy-3-t-butyl-5-methylphenyl propane;

bis Z-hydroxy-3-t-butyl-5-methylphenyl -butane;

bis S-hydroxy- 3-t butyl-5-methylphenylisobutane 1, l-bis 6-hydroxy-5-t-butyl-3-methylphenyl methane;

bis (z-hydroxy-5-t-butyl-3-mehtylpheny1) ethane;

1, 1 -bis 2-hyd roxy-S-t-butyI-B-methylphenyl propane;

l, 1 -bis 2-hydroxy-5-t-amyl-3-methylphenyl) butane;

1, 1 -bis Z-hydroxy-S-t-amyl-3-methylphen yl isobutane;

etc.

The referred bisphenol is 4,4'-methylene bis(2,6ditert, butylphenol) Minor amounts of each class of additives are sufficient for a highly elfective combination. The nitrogen containing copolymer and the complex diamide-phosphate or alkyl phenoxy earboxylic acid may be used in an amount of about 01-10%, preferably about 0.25% by weight each of the lubricant, while about ODS-2%, preferably about 0.1l% of the methylene bisphenol is highly useful.

The additive combinations of the present invention may be used to improve various hydrocarbon lubricating oils, whether of natural origin or synthetic, especially oils which are substantially parafiinic and/or naphthenic; they may contain substantial proportions of hydrocarbons having aromatic character but the amounts and types of components should be such that the Dean and Davis (Chem. and Met. Eng, vol. 36, 1929, pp. 618-619) viscosity index of the base oil is at least 80, preferably at least to 150.

The oil may be derived from a highly paratllnic crude, in which case distillation and/or dewaxing may be sufficient to provide a suitable base stock; a minimum of chemical or selective solvent treatment may be used if desired. Mixed base crudes and even highly aromatic crudes which contain paratfinic hydrocarbons also provide suitable oil base stocks by well known refining techniques. Usually these comprise the separation of distillate fractions of suitable boiling range followed by selective solvent extraction with solvents such as furfural, phenol and'the like to provide raffinate fractions which are suitable for further refining by dewaxing and chemical treatment such as sulfuric acid treatment, etc. Thus, it may Other representative non-ash forming lubricating compositions of the present invention include mineral oil containing:

H-2.5% copolymer of Example I+0.5% of Complex IIe I2% copolymer of Example II+0.25%'ofComplex J5% of copolymer of stearyl methacrylate/lauryl metha-crylate/Lmethyl 5 vinyl py ridine+'.75% of Complex 110 Compositions A, B, E and F of the present invention and comparative compositions shown in the table were tested (1) in the Oldsmobile Scufiing Test under conditions described in the October 6, 1959, Report issued by Technical Committee B of ASTM Committee D-2 entitled Engine Test Sequence for Evaluating Oils for API Service M85 and engine scutfing was visually rated as 1 to 10 with 10 being perfect and 1 being poor; (II) Exhaust Gas Rust Test (EGRT) which comprises exposing oil-dipped steel panels to the exhaust vapors of a single cylinder 4-cycle Briggs and Stratton engine operbe a refined hydrocarbon oil obtained from a paraifinic, 5

naphthenic, asphaltic or mixed base crude, and/or mixtures thereof, such as SAE 5W, W, 20W, 20, 30, 40,

50 mineral oils. The hydrocarbon oils may be blends of difierent mineral oil distillates and bright stock; they may have blended therewith a minor but compatible 10 proportions fixed oils, such as castor oil, lard oil and the like and/or with synthetic lubricants, such as polymerized olefins, e.g., polyisobutylene.

The following compositions are representative of the invention.

Composition A: Percent Complex Ib 1.4 Ex. I polymer 5.0 Bis(3,5-ditert.butyl-4-hydroxyphenyl)methane 0.5 Mineral lubricating oil (SAE 30) Balance Composition B:

Complex 10 1 Ex. II copolymer 5.0 Bis(3,5-ditert.butyl-4-hydroxyphenyl)methane 0.5 Mineral lubricating oil (SAE Balance Composition C:

Complex Id 1.5 Copolymer of N-vinyl pyrrolidone/lauryl methacrylate 5 30 Bis(3,5-ditert.butyl-4-hydroxyphenyl)methane 0.5 Mineral lubricating oil (10W-30) Balance Composition D:

Complex Ib 1.4 Copolymer of Ex. II 5.0 Mineral lubricating oil (SAEZO) Balance Composition B:

Complex 1141 1.5 Copolymer of Ex. II 5.5 Bis(3,5-ditert.butyl-4-hydroxyphenyl)methane 0.5 Mineral lubricating oil Balance Composition F:

' Complex of Nb 1 Copolymer of Ex. II 5.5 Mineral lubricating oil Balance Composition G:

Complex of 1b 2 Copolymer of Ex. I 5 Bis(3,5-ditert.butyl-4hydroxyphenyl')methane 0.5 Mineral lubricating oil Balance ating on a high sulfur (1%) fuel. The panels are exposed to the hot exhaust gases for 30 minutes, then cooled to a temperature of 0 F. for 16 hours and allowed to warm to room temperature. The cycle is then repeated before inspection and rated on a scale of 1 to 10, where l is poor and 10 is perfect; and (III) GMMS Test Sequences IllI under the following 1960 conditions: Engine test conditions Sequence I Sequence II Sequence III Hours 30 cycles, 60 cycles,

10 mini 3 hrs. 40 cycles running, running, 50 min. down 3 llI'S.*(10WIl Rpm 3150125.. 3400520. Water out., F. 200i2 200512 Water iu, F 190 min. 190 min Oil temp., F 280:1:2 205:1;2 Loa'i, B.H.P.... 30 :1:2. Air/fuel 14.5;i;0.5 15:1;05. Blow-by rate O 2.05:0.2 c.f.m. Exhaust back in. 203:4 in.

water. water water.

and the results were as follows:

TABLE I Test 1 II III Oldsmobile GM-MS scuiling EGRT test. final test. visual test (10: rating 1 rating (10 perfect) (100:

perfect) perfect) 9 9 89 9 9 88. 8 9 9 90 8 8 85 (1) Mineral lubricating oil plus 1% of dioleyl amide of H3NC l'[2ClI2-N (CJUB) ClI2C|lzNlIz(l(1) 2 (1-2) 3 (2) Mineral lubricating oil plus 1% mixture of inonoalkyl dilauryl acid phosphate c 2 (Hi) 4 00 (3)' Mineral lubricating oil plus 2% l-hy(lrox v ethyl-2410mm decenyl iniidiazolinc plus 2% nonyl phenoxy acetic acid 2 (1-3) 2 75 (4) Mineral lubricating oil plus 4% i-hydroxy ethyl-J-heptadeeenyl llllltllflZOllllB 2 (1-3) 2 70 (5) Mineral lubricating oil plus 2% Ex. II copolymer 2 (1-3) 1 70 (6) Mineral lubricating oil 4 70 .soluble polymeric nitrogen-containing detergent selected fromthe group consisting of an oil-soluble copolymer of C-vinyl'pyridine and a long chain alkyl methacrylate and an oil-soluble copolymer of N-vinyl pyrrolidone and a long chain alkyl methacrylate and an oil-soluble complex of a diamide having the formula and an acidic compound selected from the group consisting of a C alkyl acid phosphate and a C alkyl phenoxy carboxylic acid where R is a C alkyl radical,

consisting of hydrogen and a C alkyl radical and n is an integer of l to 10.

2. A mineral lubricating oil composition consisting and a C alkyl phenoxy carboxylic acid where R is C alkyl radical, R and R are independently selected from the group consisting of hydrogen and C alkyl radical and'n is an integer of from 1 to 10.

4. A mineral lubricating oil composition consisting essentially of a major amount of mineral lubricating oil and from about 0.1% to about each of an oilsoluble copolymer of C-vinyl pyridine and a mixture of dissimilar long chain alkyl methacrylates and an oilsoluble complex of dioleyl amide of and a mixture of mono and dilauryl acid phosphate.

5.. A mineral lubricating oil composition consisting essentially of a major amount of mineral lubricating oil and from about 0.1% to about 10% each of an oil-soluble copolymer of C-vinyl pyridine and a mixture of dissimilar long chain alkyl methacrylates and an oil-soluble complex of dioleyl amide of H NCH CH N(C H )CH CH NH and nonyl phenoxy acetic acid.

6. A mineral lubricating oil composition consisting essentially of a major amount ofmineral lubricating oil and from about 0.1 to about 10% each of an oil-soluble copolymer of C-vinyl pyridine and" a mixture of dissimilar long chain alkyl methacrylates and an oil-soluble complex of dioleyl amide of N-Z-aminoethyl piperazine and a mixture of mono and dilauryl acid phosphate.

7. A mineral lubricating oil composition consisting essentially of a major amount of mineral lubricating oil and from about 0.1% to about 10% each of an oil-soluble copolymer of C-vinyl pyridine and a mixture of dissimilar long chain alkyl methacrylates and an oil-soluble complex of dioleyl amide of N-Z-aminoethyl piperazine and nonyl phenoxy acetic acid.

8. A mineral lubricating oil composition consisting essentially of a major amount of mineral lubricating oil and from about 0.1% to about 10% each of an oilsoluble copolymer of 2-methyl-5-vinyl pyridine and a mixture of lauryl and stearyl methacrylates and an oilsoluble complex of dioleyl amide of and a mixture of mono and dilauryl acid phosphate.

9. A mineral lubricating oil composition consisting essentially of a major. amount of mineral lubricating oil and from' about 0.1% to about 10% each of an oilsoluble copolymer of 2-methyl-5-vinyl pyridine and a mixture of lauryl and stearyl methacrylates and an oilsoluble complex of dioleyl amide of and nonyl phenoxy acetic acid.

10,. A mineral lubricating oil composition consisting essentially of a major amount of mineral lubricating oil and from about 0.1% to about 10% each of an oil-soluble copolymer of 2-methyl-5-vinyl pyridine and a mixture of lauryl and stearyl methacrylates and an oil-soluble complex of dioleyl amide of N-Z-aminoethyl piperazine and nonyl phenoxy' acetic acid.

11. A mineral lubricating oil composition consisting essentially of a major amount of mineral lubricating oil and from about 0.1% to about 10% each of an oil-soluble copolymer of Z-methyl-S-vinylpyridine and a mixture of lauryl and stearyl methacrylates and an oil-soluble complex of dioleyl amide of N-2-aminoethyl piperazine and a mixture of mono and dilauryl acid phosphate.

12. The composition of claim 8 containing from about 0.05% to 2% of bis(3,5-ditertbutyl-4-hydroxyphenyl)- methane.

13. The composition of claim 9 containing from about 0.05 to 2% of bis(3,5-ditertbutyl-4-hydroxyphenyl)- methane.

14. The composition of claim 10 containing from about 0.05% to 2% of bis(3,5-ditertbutyl-4-hydroxyphenyl)- methane.

15. The composition of claim 11 containing from about 0.05 to 2% of bis(3,5-ditertbutyl-4-hydroxyphenyl)- methane.

References'Cited by the Examiner .;UNITED STATES PATENTS 10/51 Herman et al. 252-49.9 3/56 Catlin 252-5l.5 4 /58 Knowles et al. 252-52 7/58 Westlund et al. 252-51.5 7/60 Hutchison 252-5l.5

12/60 Ries 252-49.8 8/63 Wittner 252-49.9

FOREIGN PATENTS 11/54 Australia. 10/ 56 Great Britain. 5/59 Great Britain.

DANIEL E. WYMAN, Primary Examiner. 

1. A MINERAL LUBRICATING OIL COMPOSITION CONSISTING ESSENTIALLY OF A MAJOR AMOUNT OF MINERAL LUBRICATING OIL AND FROM ABOUT 0.1% TO ABOUT 10% EACH OF AN OILSOLUBLE POLYMERIC NITROGEN-CONTAINING DETERGENT SELECTED FROM THE GROUP CONSISTING OF AN OIL-SOLUBLE COPOLYMER OF C-VINYL PYRIDINE AND A LONG CHAIN ALKYL METHAORYLATE AND AN OIL-SOLUBLE COPOLYMER OF N-VINYL PYRROLIDONE AND A LONG CHAIN ALKYL METHACRYLATE AND AN OIL-SOLUBLE COMPLEX OF A DIAMIDE HAVING THE FORMULA 